Problem: Express your answer as a mixed number simplified to lowest terms. $11\dfrac{6}{9}-5\dfrac{2}{5} = {?}$
Solution: Separate the whole numbers from the fractional parts: $= {11} + {\dfrac{6}{9}} - {5} - {\dfrac{2}{5}}$ Bring the whole numbers together and the fractions together: $= {11} - {5} + {\dfrac{6}{9}} - {\dfrac{2}{5}}$ Subtract the whole numbers: $=6 + {\dfrac{6}{9}} - {\dfrac{2}{5}}$ Simplify each fraction: $= 6 + {\dfrac{2}{3}} - {\dfrac{2}{5}}$ Find a common denominator for the fractions: $= 6+\dfrac{10}{15}-\dfrac{6}{15}$ Subtract the fractions: $= 6+\dfrac{4}{15}$ Combine the whole and fractional parts into a mixed number: $= 6\dfrac{4}{15}$